Add blueMSX info

Adding blueMSX info file, please give it a once-over:
- libretro.c only mentions rom|mx2 for supported filenames, it might support more. (mx1/col/dsk)
- Manufacturer is various since there were a lot of MSXes
- License includes some GPLv2 stuff, some zlib stuff, and some BSD stuff
- Don't know if firmware is required, have not tested
- We're working from svn source so svn is the version
- Fullpath is specified in libretro.c